"We wouldn't be sitting here if I didn't come back," he told Winfrey.
In 2011, Armstrong retired once more from cycling. But his fight to maintain his clean reputation wasn't over, including a criminal investigation launched by federal prosecutors.
That case was dropped in February. But in April, the U.S. Anti-Doping Agency notified Armstrong of an investigation into new doping charges. In response, the cyclist accused the organization of trying to "dredge up discredited" doping allegations and, a few months later, filed a lawsuit in federal court trying to halt the case.
In retrospect, Armstrong told Winfrey he "would do anything to go back to that day."
"Because I wouldn't fight, I wouldn't sue them, I'd listen," he said, offering to speak out about doping in the future.
The USADA found "overwhelming" evidence that Armstrong was involved in "the most sophisticated, professionalized and successful doping program."
In August, Armstrong said he wouldn't fight the charges, though he didn't admit guilt either.
And the hits kept on coming.
In October, the International Cycling Union stripped him of all his Tour de France titles. Even then, he remained publicly defiant, tweeting a photo of himself a few weeks later lying on a sofa in his lounge beneath the seven framed yellow jerseys from those victories.
Then the International Olympic Committee stripped him of the bronze medal he won in the men's individual time trial at the 2000 Olympic Games and asked him to return the award, an IOC spokesman said Thursday.
The USOC was notified Wednesday that the IOC wants the medal back, USOC spokesman Patrick Sandusky said.
"We will shortly be asking Mr. Armstrong to return his medal to us, so that we can return it to the IOC."